Polyurethane biological sample collection and transport device and its use

ABSTRACT

A microbiological culture collection and transport device maintains viable organisms for periods of time longer than possible with existing sampling devices. It also allows recovery of detectable antigen at levels not achievable with conventional swabs. The new device has a sterile swabbing tip made with a non-toxic polyurethane foam having open cells at its exposed surface. It does not require a transport medium and can be used dry. The device may further include a sample inoculator to distribute organisms collected onto a solid or semi solid medium. Methods for collecting and transporting microbiological specimens and for recovering detectable antigen are also described.

This is a divisional of application Ser. No. 07/508,506 filed Apr. 11,1990 which is a continuation of Ser. No. 07/346,142, filed May 4, 1989,now abandoned which is a continuation in part of Ser. No. 07/204,431filed Jun. 9, 1988 now abandoned.

FIELD OF THE INVENTION

The present invention relates to devices for collecting and transportingbiological specimens. More particularly, it relates to an improved swabfor collecting samples and a simplified transport device incorporatingthe improved swab.

BACKGROUND OF THE INVENTION

Detecting the presence of pathogenic microbial species requires, as afirst step, collection of an appropriate sample. Typically a sterilecollection device such as a swab is used. In the past, these swabs havebeen made of various materials such as cotton, sheep wool, polyester andrayon.

After the sample has been collected on a swab it is transported to amicrobiology laboratory where any organisms present are identified. Theidentification method may be conventional culturing followed byidentification or immunometric assay. A persistent problem for samplesto be cultured has been maintaining viability of pathogenic organisms.Where the sample is to be processed for an immunoassay, a persistentproblem has been recovery of immunological active material.Additionally, the sample needs to be protected from contamination by theenvironment during transport. Numerous devices have been devised thatprovide both a means for obtaining the sample and means for protectingthe sample during transport. Most often these devices comprise aswabbing element having a shaft typically of wood or plastic and aswabbing tip which has universally been produced from fibrous materialsuch as cotton fibers, wool, polyester fibers or rayon fibers.

Further elements common to most devices are a cap to which the shaft isfixed and which mates with a lower swab cover to protect the swabbingtip both before and after collection of sample and a liquid mediumcontaining reservoir such as a frangible glass ampoule that can bebroken to release aqueous medium to keep the swab and sample moist.Representative collection and transport devices are shown in U.S. Pat.Nos. 4,223,093 (to Newman et al.), 4,030,978 (to Abramson), 4,175,008(to White), 4,311,792 (to Avery), and 4,014,748 (to Spinner et al.).

Media described by Stuart et al. "The Problem of Transport of Specimensfor Culture of Gonococci," Can. J. Pub. Health, vol. 45, pp. 73 83(1954) and a later modification by Amies "A Modified Formula for thePreparation of Stuart's Transport Medium", Can. J. Pub. Health, vol. 58,pp. 296-300 (1967) are examples of growth maintenance media which do notpromote growth that are commonly employed. Such media preserve theorganisms present in the specimen while retarding or preventing growthduring transport.

The medium is often retained inside the specimen collection device andadjacent to the specimen collection swabbing tip by an absorbent fibrousswatch of material. This swatch or pledget, as it is often named, can bea woven or non woven section of fabric or a piece of fibrous materialsuch as cotton or rayon. While serving to restrain the flow of theaqueous media and prevent dehydration of the collected sample, thepledget materials such as cotton, polyester or rayon currently utilizeddo not enhance and may possibly be detrimental to preserving theviability of the microorganisms collected.

Several studies have attempted to evaluate the toxic nature of variousfibrous materials used in the swab and also employed in the pledget.Studies are reported by Ellner et al. "Survival of Bacteria On Swabs",J. Bacteriol., vol. 91, pp. 905-6 (1966); Barry et al. "Efficiency of aTransport Medium for the Recovery of Aerobic and Anaerobic Bacteria fromApplicator Swabs," Appl. Micro.Bio., vol. 24, pp. 31 3(1972); Ross etal. "Swabs and Swab-Transport Media Kits in the Isolation of UpperRespiratory Bacteria," J. Clin. Pathol. vol. 35, pp. 223-7 (1982); Rubboet al. "Some Observations on Survival of Pathogenic Bacteria on CottonWool Swabs," Brit. Med. J., pp. 983-7 (May 1951), and Anderson"Antibacterial Bacteriological Swabs", Brit. Med. J., pp. 1123-4 (Nov.1965).

Certain devices have eliminated the need for a liquid retaining pledgetby substituting an agar containing medium for the liquid medium. Theagar produces a gelled or highly viscous medium into which the specimenswab is placed after collecting the sample. The agar medium providesprotection, but leads to agar residue on the swab. This residue cansubsequently interfere with analytical procedures such as specimenstaining for visual microscopic detection of organisms. Agar has alsobeen found to interfere with certain latex agglutination tests commonlyemployed. Stuart et al. (cited above) have shown agar to be toxic tocertain organisms.

A very recent study, Appelbaum, Peter C. et al., "Survival of Bacteriain Difco CultureSwab and Marion Culturette II Transport Systems," J.Clin. Micro. Biol., .vol. 26, pp. 136-8 (1988), typifies the commercial"state of the art" in describing two commonly available commercialsystems with fibrous swabs and a media component. This study points outthat 90% of the organisms cannot be recovered from either wet systemafter four hours storage time.

Devices having a liquid transport medium are expensive to make becausethey have multiple elements which must be formulated or made and thenassembled. The devices with agar transport medium are less thanacceptable because the agar interferes with subsequent testing. Thus, asubstantial need exists for collection and transport devices that willyield viable organisms after four hours storage time.

The prior art clearly discourages the use of dry swabs. Similarly, ituniversally utilizes fibrous swabs of cotton, wool, rayon, polyester,and calcium alginate. Among the materials not previously used in swabsfor collecting and transporting microorganism is polyurethane. At leastone study, Bach, John A., et al., "Inhibition of Microbial Growth byFatty Amine Catalysts from Polyurethane Foam Test Tube Plugs", Appl.Micro. Biol., vol. 29 no. 5, pp. 615-620 (1975), has concluded that thematerial is not suitable for use when culturing microorganisms becauseautoclaving the polyurethane releases substances which are toxic tomicroorganisms.

Another acknowledgment that polyurethane may harm an organism withprolonged contact is found in U.S. Pat. No. 4,401,130 to Halford et al.That patent addresses the problem of joining a polyurethane foam swab toits stick without leaving dust which it characterizes as "possiblydangerous when open wounds are subject to treatment using the swabs."Col. 2, lines 27-8.

Polyurethane has been used in other health care applications. Forexample, one brand of contraceptive sponge is made from a special gradeof polyurethane foam made from a foamable hydrophilic prepolymer resinavailable from W. R. Grace & Co. and sold with the trademark Hypol.These resins are derived from toluene diisocyanate and methylenediphenyldiisocyanate. They have also been used in wound dressings. The polymersmade from these resins are said to have no extractable toluene diamine,toluene diisocyanate, or other primary aromatic amines.

Polyurethane is recommended for use in a unitary molded swab describedin U.S. Pat. No. 3,871,375. That patent states that the swab may be usedfor "application of medication, the removal of earwax, and all of theother uses for which swabs are normally employed." Col. 2, lines 16-18.It also states that the swab may be sterilized. It does not suggest usefor collecting biological specimens and therefore does not address theknown toxicity of polyurethane to microorganisms.

Additionally, polyurethane foam has been reported to be useful as a swabtip for removing foreign materials from a surface and to apply fluidssuch as paint, cosmetics, and medicines. U.S. Pat. No. 3,724,018describes a swab made with a reticulated plastic foam material, such aspolyurethane foam, wrapped around an end of a stick. The patent does notaddress sterilizing the swab or the known toxicity of polyurethane tomicroorganisms.

SUMMARY OF THE INVENTION

Surprisingly, many of the problems associated with existing devices aresolved by using as the swabbing material a polyurethane foam which isnon toxic as demonstrated by a lack of a zone of growth inhibition whenplaced on a semi-solid growth medium smeared with a suspension of N.meningitidis (Quality Control Collection, Becton Dickinson MicrobiologySystems, ATCC 53900), N. gonorrhoeae (ATCC 19424) or N. gonorrhoeae(ATCC 43070) and which has open cells at its exposed surface. The newswab is comprised of a shaft and a sterile swabbing tip secured to oneend of the shaft. The swabbing tip is formed with a polyurethane foamwhich is non toxic as demonstrated by a lack of a zone of growthinhibition when placed on a semi solid medium smeared with a suspensionof N. meningitidis (Quality Control Collection, Becton DickinsonMicrobiology Systems, ATCC 53900), N. gonorrhoeae (ATCC 19424) or N.gonorrhoeae (ATCC 43070) and which has open cells at its exposedsurface.

This new swab can be used in a collection and transport device that ismuch simpler than existing devices. The new collection and transportdevice of the present invention comprises the new swab together with acap secured to the end of the shaft opposite the swabbing tip and atubular swab cover which covers the swab and mates with the cap toprotect the swab from the environment. The collection and transportdevice may be free of any transport medium.

In a further aspect of the invention a sample inoculator is provided.Preferably the sample inoculator is secured to the exterior of the capand a inoculator cover is provided to protect the inoculator fromcontamination prior to use.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows the transport and collection device of the presentinvention; and

FIG. 2 shows a detail in cross section of the swabbing tip of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

As shown in the figures, the swab 9 of the present invention has a shaft10 and a swabbing tip 11. The swab is secured to a cap 12 that mateswith a swab cover 13 to form a slidable seal. An optional sampleinoculator 15 is attached to cap 12 and protected by inoculator cover14. While the inoculator is shown in an elliptical shape, those skilledin the art will appreciate that a variety of geometries can be used. Forexample, the inoculator could be formed as a cube or a tetrahedron.

The transport and collection device of the present invention does notrequire a liquid or solid transport medium. Elimination of theseelements makes manufacture and assembly of the device much easier andtherefore less expensive than manufacture and assembly of presentlyexisting devices. The preferred foams used in the present invention canbe sterilized with autoclaves opening up the possibility of using thissterilization procedure if appropriate materials are used for theremaining components of the transport device. The addition of sampleinoculator 15 and inoculator cover 14 further enhances the usefulness ofthe device.

A variety of lengths and materials are possible for shaft 10 for examplewood, plastic or wire might be utilized. Similarly the cap 12, swabcover 13, and sample inoculator 15 can be made of materials well knownto those skilled in the art.

The advance of the present invention is use for the swabbing tip 11 of-a sterile polyurethane foam which is non toxic as demonstrated by a lackof a zone of growth inhibition when placed on a semi solid growth mediumsmeared with a suspension of N. meningitidis (Quality ControlCollection, Becton Dickinson Microbiology Systems, ATCC 53900), N.gonorrhoeae (ATCC 19424) or N. gonorrhoeae (ATCC 43070) and which hasopen cells on its exposed surface. Swabs which are found to be non toxicto these three organisms after incubations on suitable semi solid growthmedia for twenty-four, twenty four and forty eight hours respectivelyhave been found to be non toxic to a wide variety of human pathogensthat are cultured from specimens collected with swabs and transported tothe microbiology laboratory under conditions typically encountered bymicrobiologists. They have also been found to provide substantialimprovement in recovery of materials that will participate in specificbinding reactions in immunoassays.

The swabbing tip has open cells at its exposed surface which in usecontacts the sampling site to collect the sample. The open cells at thesurface may be achieved by using a reticulated foam or by using a nonreticulated foam and shearing the cells at the surface to create opencells. Preferably the foam has 20 to 200 pores per inch (8 to 80 poresper cm) at the surface and the cells fall within a size range of 0.0196mm to 0.196 mm average diameter. Most preferably cells having an averagediameter greater than 0.2 mm should be avoided. Shearing of a nonreticulated foam to create open cells at the surface may convenientlyoccur in a fabrication step whereby large blocks of foam are cut to sizefor attachment to the shaft. The swabbing tip 11 may have an inner core16 to facilitate attachment and manufacture or may be attached directlyto shaft 10.

The foam should be a medical grade foam substantially free of leachablemonomers that can be toxic to microorganisms. Particularly preferred arefoams sold under trade designations "SCOTFOAM Custom Foam", "SCOTFOAMCustom Foam CL", and "SCOTFOAM Special Pore Custom Foam" having 60 to100 pores per inch (24 to 40 pores per cm) in either pigmented orunpigmented form (all from SCOTFOAM Corp., Eddystone, Pa.).

The unexpected and unique ability of the polyurethane foam to maintainviable microorganisms without an aqueous medium and a pledget is mostunexpected. Nothing in the prior art of microbio logical swabs orpolyurethane foams suggests that the polyurethane foam will provide adevice that maintains the viability of microorganisms for periods equalor greater to the periods for which a medium wetted fiber swab canmaintain such organism viability.

The unexpected benefits of the invention and other features of theinvention will be appreciated from the following nonlimiting examples.In Examples 1 to 5 microorganisms used were obtained from the sourcesshown in Table I.

                  TABLE I                                                         ______________________________________                                        MICROORGANISM STRAINS UTILIZED                                                CODE      TEST ORGANISM    SOURCE.sup.a, b, c                                 ______________________________________                                        CAL       Candida albicans QCC, BDMS                                          ESC       Escherichia coli ATCC 25922                                         GCA       Neisseria gonorrhoeae                                                                          ATCC 19424                                         GCB       Neisseria gonorrhoeae                                                                          ATCC 35201                                         GCC       Neisseria gonorrhoeae                                                                          ATCC 43070                                         HIA       Haemophilus influenzae                                                                         ATCC 35056                                         HIB       Haemophilus influenzae                                                                         CI, JHH                                            NMA       Neisseria meningitidis                                                                         ATCC 53900                                         NMB       Neisseria meningitidis                                                                         ATCC 13090                                         PAA       Pseudomonas aeruginosa                                                                         ATCC 27853                                         PRM       Proteus mirabilis                                                                              ATCC 12453                                         SAC       Salmonella cholerasuis                                                                         ATCC 10708                                         SGB       Streptococcus Group B                                                                          ATCC 10586                                         SGD       Streptococcus Group D                                                                          ATCC 10541                                         SHS       Shigella sonnei  ATCC 9290                                          SPA       Streptococcus pyogenes                                                                         ATCC 10389                                         SPB       Streptococcus pyogenes                                                                         QCC, BDMS                                          SNA       Streptococcus pneumoniae                                                                       ATCC 6305                                          SNB       Streptococcus pneumoniae                                                                       CI, JHH                                            STA       Staphylococcus aureus                                                                          ATCC 25923                                         VBP       Vibrio parahaemolyticus                                                                        QCC, BDMS                                          YRE       Yersinia enterocolitica                                                                        QCC, BDMS                                          ______________________________________                                         .sup.a ATCC = American Type Culture Collection                                .sup.b QCC, BDMS = Quality Control Collection, Becton Dickinson               Microbiology Systems, Cockeysville, MD 21030                                  .sup.c CI, JHH = Clinical Isolate, Johns Hopkins Hospital, Baltimore, MD.

COMPARATIVE EXAMPLE 1

The sterile swabbing tip made with a non toxic polyurethane foam havingopen cells at its exposed surface and the simplified collection andtransport device of the present invention were compared to commerciallyavailable products. Fastidious organisms used were Haemophilusinfluenzae, Neisseria meningitidis and Neisseria gonorrhoeae. The nonfastidious organisms Streptococcus pyogenes (Group A Strep) andStreptococcus pneumoniae were also studied. Two different strains ofeach fastidious and non fastidious organisms, A and B, were studied.Table I identifies the actual strains and their sources. These organismsare all common potential human pathogens and are typical of the type oforganism which may be sampled from a patient with a swab.

First the bacteria were grown in a broth culture medium. Then asuspension of each organism was diluted and its turbidity was measuredin a spectrophotometer. The technique of quantitative plate counts wasutilized to construct a graph relating the measured optical density tothe number of organisms present. Thereafter, the number of organisms ina suspension was estimated by measurement of the optical density of thesuspension and reading the concentration from the corresponding graph.

Suspensions were produced that contained approximately 5×10⁷ colonyforming units (CFU) per milliliter (ml). Each swab tested was inoculatedby placing a 0.1 ml aliquot of the standard suspension in a sterile testtube, inserting the swab and allowing the aliquot to absorb into theswabbing tip.

In this experiment, swabs were from commercially available products, arayon swab provided with the Culturette™ Collection and Transport System(Marion Scientific, Kansas City, Mo.) and a mini size bondedpolyurethane foam tip swab commonly sold for cleaning electronicsurfaces (The Texwipe Co., Upper Saddle River, N.J. catalog no. TX710).These polyurethane swabs are made with a non reticulated foam which hasopen cells at its exposed surface. The rayon swabs were providedsterile. The polyurethane swabs were sterilized by gamma radiation priorto use. The inoculated rayon tipped swabs were returned to the transporttube and activated in accordance with the manufacturer's directions tobring the medium into contact with the pledget and swabbing tip. Theinoculated polyurethane foam tipped swabs were placed individually insterile screw capped plastic tubes. Multiple swabs were inoculated forstreaking at the various time intervals.

Replicate samples of each type swab were stored aerobically at ambienttemperatures. At timed intervals of 0, 4, 8, 24 or 48 hours, dependingon the organism under study, the swab was used to inoculate a petriplate of an appropriate nutritive agar medium. Each inoculated plate wassystematically streaked with a bacteriological loop according to thesemi quantitative "four quadrant method" commonly practiced by thoseskilled in the art of microbiology. Specifically, the plate wasinoculated by:

A. Rolling the swab thoroughly over a first quadrant of the plate.

B. Using a standard bacteriological loop, streak back into quadrant 1eight times.

C. Flame loop and streak back into quadrant 2 four times.

D. Streak back into quadrant 3 twice.

The inoculated plated media were incubated at 37° C. in an atmosphereenriched with 5% carbon dioxide. After twenty four to forty eight hours,the plates were observed for growth and graded according to thefollowing scheme:

4=Growth in quadrant 4 (20 to 100 colonies)

3=Growth in quadrant 3 (20 to 100 colonies)

2=Growth in quadrant 2 (20 to 100 colonies)

1=Growth in quadrant 1 (20 to 100 colonies)

+=Heavy growth (greater than 100 colonies)

=Light growth (less than 20 colonies)

The results of this experiment are summarized in Table II (average scorefor duplicate runs). For each strain for each organism tested, use ofthe polyurethane swab demonstrated improved recovery of the organismsover that obtained from the rayon swab. Additionally, for 7 of 10organisms studied the use of the polyurethane swab allowed recovery attime periods where the rayon swab showed no growth.

                  TABLE II                                                        ______________________________________                                        RECOVERY OF ORGANISMS FROM MARION                                             CULTURETTE COLLECTION AND TRANSPORT                                           DEVICE AND POLYURETHANE FOAM TIP SWABS                                                              Recovery at Elapsed                                     Organism  Swab        Storage Time (HR)                                       Strain    Material    0       4     8     24                                  ______________________________________                                        HIA       Rayon       3-      1-    0     0                                             Polyurethane                                                                              4-      3-    2     1-                                  HIB       Rayon       3       2-    1     0                                             Polyurethane                                                                              4-      3     3-    1+                                  NMA       Rayon       2       1-    0     0                                             Polyurethane                                                                              3-      2+    2-    1+                                  NMB       Rayon       4-      1+    1-    0                                             Polyurethane                                                                              3-      3-    3-    2                                   GCA       Rayon       2       0     0     0                                             Polyurethane                                                                              3-      1-    1-    0                                   GCB       Rayon       2-      0     0     0                                             Polyurethane                                                                              2-      1     1-    0                                   SPA       Rayon       2       1     0     0                                             Polyurethane                                                                              2       2     2     1+                                  SPB       Rayon       3-      2+    1+    1+                                            Polyurethane                                                                              3-      2+    3-    2-                                  SNA       Rayon       2       2-    1     1+                                            Polyurethane                                                                              3-      3-    3-    3-                                  SNB       Rayon       3-      1+    1-    1-                                            Polyurethane                                                                              3-      2+    2-    1                                   ______________________________________                                    

EXAMPLE 2

In this example, the sterile swabbing tip made with a non-toxicpolyurethane foam having open cells at its exposed surface and thesimplified collection and transport device of the present invention werecompared to another commercially available sterile swabbing tip. The BBLPort A Cul™ Aerobic Transport Device (Becton Dickinson MicrobiologySystems, Cockeysville, Md.), has a rayon tipped swab, a rayon pledgetand a medium following the formulation of Amies. The devices aresterilized by gamma radiation. After inoculation of the rayon swabs asin Example 1, the swabs were returned to the Port-A device and activatedaccording to the manufacturer's directions. The polyurethane swabs usedand their method of inoculation and storage were as in Example 1. Thesetests were conducted with a similar panel of organisms as was used inExample 1. The results are shown in Table III (average score forduplicate runs). Here again a pattern of improved organism recoverythrough use of the polyurethane swabs over that obtained from the rayonswabs was observed. For some organisms, the use of the polyurethaneswabs allowed recovery at time periods where the rayon swabs showed nogrowth.

                  TABLE III                                                       ______________________________________                                        RECOVERY OF ORGANISMS FROM BBL PORT-A-CUL                                     AEROBIC TRANSPORT DEVICES AND                                                 POLYURETHANE FOAM TIP SWABS                                                                         Recovery at Elapsed                                     Organism  Swab        Storage Time (HR)                                       Strain    Material    0       4     8     24                                  ______________________________________                                        HIA       Rayon       3-      1-    1-    0                                             Polyurethane                                                                              3-      3-    2+    2-                                  HIB       Rayon       3       2-    1     0                                             Polyurethane                                                                              3-      3-    3-    2                                   NMA       Rayon       3-      1-    0     0                                             Polyurethane                                                                              3-      3-    2+    2-                                  NMB       Rayon       4-      2-    1     0                                             Polyurethane                                                                              4-      4-    3-    2+                                  SPA       Rayon       3       2+    2     2-                                            Polyurethane                                                                              3-      2+    2     2-                                  SPB       Rayon       3       3-    2+    3-                                            Polyurethane                                                                              4-      3     2+    3-                                  SNA       Rayon       3-      2+    2-    1                                             Polyurethane                                                                              3-      3-    2+    2                                   SNB       Rayon       3-      2+    2-    1                                             Polyurethane                                                                              2       3-    2-    1                                   ______________________________________                                    

EXAMPLE 3

The sterile swabbing tip made with a non toxic polyurethane foam havingopen cells at its exposed surface and the simplified collection andtransport device of the present invention were compared again to acommercially available swabbing tip. The procedure followed and thecommercially available rayon tip were identical to those of Example 2.The organisms were different. An additional 11 bacterial species and 1yeast species were tested. The organisms are all potential humanpathogens which can be collected from a patient using a swab collectionand transport device. The results of this experiment are summarized inTable IV (average score for duplicate runs). With seven of elevenorganisms studied, recovery from the polyurethane swab was equal to orbetter than that observed with the BBL Device, though recovery of allorganisms was observed at 48 hours with both type swab sample devices.

                  TABLE IV                                                        ______________________________________                                        RECOVERY OF PATHOGENIC AND OPPORTUNISTIC                                      ORGANISMS FROM BBL PORT-A-CUL AEROBIC                                         TRANSPORT DEVICES AND POLYURETHANE                                            FOAM TIP SWABS                                                                                      Recovery at Elapsed                                     Organism  Swab        Storage Time (HR)                                       Strain    Material    0        24    48                                       ______________________________________                                        PAA       Rayon       3-       3     4-                                                 Polyurethane                                                                              3-       4-    3                                        ESC       Rayon       2        2+    2                                                  Polyurethane                                                                              3-       3-    3-                                       SAC       Rayon       4-       2     2-                                                 Polyurethane                                                                              4        3     3+                                       SHS       Rayon       3-       2+    2-                                                 Polyurethane                                                                              4-       3     2+                                       PRM       Rayon       4-       3-    2                                                  Polyurethane                                                                              4-       3-    3                                        VBP       Rayon       2        2-    1-                                                 Polyurethane                                                                              2        4-    3-                                       YRE       Rayon       2        2-    2+                                                 Polyurethane                                                                              2        4-    1+                                       STA       Rayon       4-       3-    2+                                                 Polyurethane                                                                              4-       3-    3+                                       SGB       Rayon       3        2+    3-                                                 Polyurethane                                                                              3-       3-    2+                                       SGD       Rayon       3        3-    2                                                  Polyurethane                                                                              3        3-    2                                        CAL       Rayon       3        4-    4-                                                 Polyurethane                                                                              3        3-    2+                                       ______________________________________                                    

EXAMPLE 4

In Examples 1, 2, and 3, the sterile swabbing tips made with a non toxicpolyurethane foam having open cells at its exposed surface which werestudied received no additional media after inoculation and duringstorage. In contrast, the rayon tipped swabs were moistened afteractivation in accordance with the instructions of their respectivemanufacturers. In this experiment, all of the swabs were stored in drytubes. The polyurethane swabs were the same as those used in Examples 1,2, and 3. Rayon tipped swabs were obtained from BBL Port A Cul™ devices(Becton Dickinson Microbiology Systems, Cockeysville, Md.) and fromCulturette™ devices (Marion Scientific, Kansas City, Mo.). Afterinoculation, all rayon swabs were stored in the storage tube supplied bythe manufacturer from which the fluid medium reservoir and pledgetmaterial were aseptically removed. Dacron tipped swab devices wereobtained commercially from American Scientific Products (McGaw Park,Ill. catalog no. A5005-1). These swabs are provided sterile in a paperpackage.

Inoculation of all swabs in this experiment with Streptococcus pyogenes(Group A Streptococcus, SPA) was as in Example 1. Each inoculated rayontipped swab was returned to its modified transport tube for storage. Thepolyurethane and Dacron swabs were placed individually in sterile screwcapped tubes for storage. Additionally wet storage experiments were runby inoculating and activating swabs from Marion Culturette™ and BBLPort-A-Cul™ devices as in Examples 1 and 2.

The results of this experiment are summarized in Table V (average scoresfor duplicate runs). Organism recovery from polyurethane swabs,sterilized by three different methods, was better than that observedwith either rayon or Dacron type swabs stored under similar dryconditions. Thus, enhanced recovery observed with the polyurethane swabsis related to type swab material and not method of storage orsterilization. Also, the use of polyurethane swabs again allowedrecovery at time periods where rayon swabs, stored under moist or dryconditions, showed no growth.

                  TABLE 5                                                         ______________________________________                                        RECOVERY OF GROUP A STREPTOCOCCI FROM                                         MOISTENED AND NON-MOISTENED SWAB DEVICES                                                                   Recovery at                                      Swab   Swab        Storage   Elapsed Time (HR)                                Source Material    Condition 0     2     4                                    ______________________________________                                        Marion Rayon       Moist     3-    2     0                                    BBL    Rayon       Moist     ND.sup.a                                                                            ND    2+                                   BBL    Rayon       Dry       3-    0     0                                    Scientific                                                                           Dacron      Dry       3     1-    1-                                   Prods.                                                                        Texwipe                                                                              Polyurethane.sup.b                                                                        Dry       3     3-    2+                                          Polyurethane.sup.c                                                                        Dry       3     3-    3+                                          Polyurethane.sup.d                                                                        Dry       3-    3-    2-                                   ______________________________________                                         .sup.a ND, not determined                                                     .sup.b Sterilized by gamma radiation                                          .sup.c Sterilized by particle beam radiation                                  .sup.d Sterilized by ethylene oxide gas                                  

EXAMPLE 5

This experiment was undertaken to demonstrate the beneficial effect ofselecting as the swabbing tip a non toxic polyurethane foam having opencells at its exposed surface. Several fastidious organisms were chosento probe for toxic effects of the swabbing material.

Bacteria used in this experiment are as identified in Table I, and mediaused for growth and toxicity testing are as listed in Table VI. Eachstrain was grown overnight on the appropriate medium at 37° C. in anatmosphere enriched with 5% carbon dioxide. A suspension of eachorganism was then prepared in saline that contained approximately1.5×10⁸ cfu/ml. For each strain the surface of the toxicity testingmedium indicated in Table 6 was systematically inoculated by a crossstreaked method, commonly practiced by those skilled in the art ofmicrobiology, so as to produce confluent growth over the surface of themedium after incubation at 37° C. in an atmosphere enriched with 5%carbon dioxide. After each plate was so inoculated, swab tip materialswere aseptically placed on the inoculated medium surface and plates wereincubated as described above.

After twenty four hours incubation for strains NMA, NMB, and SPA andforty eight hours incubation for strains GCA and GCC, the plates wereexamined for a zone of growth inhibition about the swabbing tipmaterial. The size of each zone of inhibition was measured and recordedin millimeters.

Rayon tipped swabs were obtained from Culturette™ devices (MarionScientific, Kansas City, Mo.) and BBL Port-A-Cul™ devices (BectonDickinson Microbiology Systems, Cockeysville, Md.). Polyurethane tippedswabs were obtained from two sources: The Texwipe Co., Upper SaddleRiver, N.J. (Catalog No. TX710) and Wilshire Foam Products, Inc., CarsonCity, Calif. (Catalog Nos. HT1001 and HT1005). The rayon swabs wereprovided sterile. The Texwipe and Wilshire HT1001 polyurethane swabswere sterilized with gamma radiation. The Wilshire HT1005 wasasceptically used as supplied.

The results of this experiment are summarized in Table VII (averagescore for duplicate runs). These results serve to differentiate amongpolyurethane type materials. The preferred type polyurethane swabbingmaterial should not be toxic. The Texwipe and Wilshire (H1001) are shownto be suitable for this purpose. Wilshire (H1005) was shown to be toxicto three of the five fastidious strains tested. For comparative purposesthis experiment also demonstrates that differing sources of rayonswabbing materials may be differentiated relative to inherent toxicity.

                  TABLE VI                                                        ______________________________________                                        MEDIA USED FOR GROWTH AND                                                     TOXICITY TESTING                                                                                      TOXICITY TEST                                         ORGANISM GROWTH MEDIUM  MEDIUM (CATA-                                         TESTED   (CATALOGUE NO.)                                                                              LOGUE NO.)                                            ______________________________________                                        NMA      CHOC II AGAR   MUELLER HINTON II                                              (BDMS 21267).sup.a                                                                           AGAR (BDMS 21800)                                     NMB      CHOC II AGAR   MUELLER HINTON                                                 (BDMS 21267)   CHOC AGAR (BDMS                                                               21802)                                                GCA      CHOC II AGAR   MUELLER HINTON                                                 (BDMS 21267)   CHOC AGAR (BDMS                                                               21802)                                                GCC      CHOC II AGAR   MUELLER HINTON                                                 (BDMS 21267)   CHOC AGAR (BDMS                                                               21802)                                                SPA      TSA II AGAR    MUELLER HINTON II                                              (BDMS 21261)   AGAR (BDMS 21800)                                     ______________________________________                                         .sup.a BDMS, Becton Dickinson Microbiology Systems, Cockeysville, MD.    

                                      TABLE VII                                   __________________________________________________________________________    DETERMINATION OF TOXIC PROPERTIES OF                                          POLYURETHANE AND RAYON SWABBING TIP MATERIALS                                                  Inhibition Zone Size (MM)                                    Swab Source                                                                          Swab Material                                                                           NMA NMB  GCA GCC  SPA                                        __________________________________________________________________________    TEXWIPE                                                                              POLYURETHANE                                                                            0   0    0   0    0                                                 (#710)                                                                 WILSHIRE                                                                             POLYURETHANE                                                                            0   0    0   0    0                                                 (#1001)                                                                WILSHIRE                                                                             POLYURETHANE                                                                            1   0    2   4    0                                                 (#1005)                                                                MARION RAYON     6   0    0   1    0                                          BBL    RAYON     0   0    0   0    0                                          __________________________________________________________________________

EXAMPLE 6

In this example, the ability to recover detectable Group A Streptococcalantigen was tested. Group A Streptococcus (Streptococcus pyogenes, ATCC12385) was grown on blood agar plates for 24 hours at 37° C. Asuspension was then prepared in saline and the turbidity was adjustedwith a spectrophotometer to obtain approximately 1×10⁹ colony formingunits (CFU) per milliliter (ml). Additional dilutions of this stocksuspension were prepared in saline so as to contain in 0.050 ml 50×10⁵,12.5×10⁵, 3.0×10⁵, 1.5×10⁵ and 0.75×10⁵ CFU. A series of swabs were theninoculated by placing a 0.050 ml aliquot of suspension in a sterile testtube, inserting the swab and allowing the aliquot to absorb into theswabbing tip. As a control for the assay system, swabs were also placedin tubes containing only 0.050 ml of saline before extraction. All swabswere tested in duplicate. Each set of duplicate swabs as well as thecontrol swabs were assayed directly for Group A streptococcal antigenusing the Directigen 1-2-3™ Group A liposome immunoassay (BectonDickinson Microbiology Systems, Cockeysville, Md.; cat. no. 8525-40). Inthis assay organisms are extracted from the swabs with nitrous acid,neutralized, and the resultant liquid extract is applied directly to amembrane containing antibody specific for Group A Streptococcus. AnyGroup A Streptococcus antigen present binds to the antibody. Afterwashing, a suspension of liposomes having antibodies to Group AStreptococcus on their surface was applied to the membrane. The presenceof antigen in the extracted material is detected by visually observing apink triangle on the membrane surface. Intensely colored triangles werescored "reactive"; faintly colored triangles were scored as "minimallyreactive"; and the absence of a visible triangle was scored as "nonreactive".

Three of the four swabs tested in this experiment were commerciallyavailable products. A dacron swab supplied with the Directigen 1-2-3™assay kit, the polyurethane swab available described in Example 1, andthe polyurethane swab described in Example 5 (Wilshire ContaminationControl, Carson, Calif.; catalog no. 1001). Also tested was anexperimental swab manufactured by Wilshire Contamination Control usingScotFoam Special Pore Custom Foam™ having 100 pores per inch (40 poresper cm) and white pigment. Each swab had an over all length of 6.0 in.(15.24 cm) and was comprised of a swabbing tip measuring about 0.625 in(1.59 cm) in length and 0.188 in. (0.48 cm) in diameter secured to awhite polystyrene shaft of 0.094 in (0.238 cm) diameter. Allpolyurethane swabs were sterilized with gamma irradiation prior to use.

The results of this experiment are summarized in Table VIII (average ofduplicate runs). In Table VIII "R" means reactive, "RM" means minimallyreactive, "N" means non reactive, and "ND" means not determined. Group Astreptococcal antigen was recoverable and detectable from foam swabshaving one fourth the quantity of organisms of the least concentratedsample from which a dectectable antigen could be recovered with thedacron swab. Thus when compared to the dacron swab utilized in theDirectigen 1-2-3™ test, the assay sensitivity was improved two to fourfold.

                  TABLE VIII                                                      ______________________________________                                        RECOVERY OF GROUP A STREPTOCOCCUS                                             ANTIGEN FROM DACRON AND                                                       POLYURETHANE FOAM TIP SWABS                                                                      ORGANISM CONCENTRATION                                     Swab    Swab       (10.sup.5 CFU)                                             Source  Material   50     12.5 3.0  1.5  0.75 0                               ______________________________________                                        Becton  Dacron     R      R    N    N    N    N                               Dickinson                                                                     Texwipe Polyurethane                                                                             R      R    R    RM   N    N                                       (#710)                                                                Wilshire                                                                              Polyurethane                                                                             R      R    R    RM   N    N                                       (#1001)                                                               Wilshire                                                                              Polyurethane                                                                             ND     R    RM   RM   RM   N                                       (experi-                                                                      mental)                                                               ______________________________________                                    

What is claimed is:
 1. A device for collecting and transportingmicrobiological samples comprising:a longitudinally extending containermember comprising an open end, a closed end, and an inside and outsidewall, without transport media; a cap comprising an exterior and interiorface being removably attachable to said open end and outside wall ofsaid container wherein said container member and said cap arelongitudinally slidable relative to each other and form a slidable seal;a shaft comprising a first and second end wherein said first end isconnected to said interior face of said cap; and a polyurethane foamswabbing tip which is non-growth inhibiting to viable microorganismsconnected to said second end of said shaft.
 2. A device for collectingand transporting microorganisms comprising:a longitudinally extendingcontainer member comprising an open end, a closed end, and an inside andoutside wall, without transport media; a cap comprising an exterior andinterior face being removably attachable to said open end and outsidewall of said container wherein said container member and said cap arelongitudinally slidable relative to each other and form a slidable seal;a shaft comprising a first and second end, wherein said first end isconnected to said interior face of said cap; and a polyurethane foamswabbing tip which is non-growth inhibiting to N. meningitidis and N.gonorrhoeae connected to said second end of said shaft.
 3. A method ofcollecting and transporting microbiological samples comprising:(a)contacting a sampling site with a polyurethane foam swabbing tip whichis non-growth inhibiting to viable microorganisms connected to a shaftcomprising a first and second end wherein the second end of said shaftis connected to a cap comprising an exterior and interior face, (b)removing a microbiological sample from said sampling site with saidswabbing tip; (c) inserting the swabbing tip with the microbiologicalsample into a protective container without transport media, saidcontainer comprising a longitudinally extending body comprising an openend, a closed end, and an inside and outside wall, wherein said open endand outside wall of said container and said cap are longitudinallyslidable relative to each other and form a slidable seal; and (d)closing said protective container with said cap to protect said swab andviable microbiological sample from the environment external of saidcontainer.
 4. A method of collecting and transporting microbiologicalsamples comprising:(a) contacting a sampling site with a polyurethanefoam swabbing tip which is non-growth inhibiting to N. meningitidis andN. gonorrhoeae, connected to a shaft comprising a first and second endwherein the second end of said shaft is connected to a cap comprising anexterior and interior face, (b) removing a microbiological sample fromsaid sampling site with said swabbing tip; (c) inserting the swabbingtip with the microbiological sample into a protective container withouttransport media, said container comprising a longitudinally extendingbody comprising an open end, a closed end, and an inside and outsidewall, wherein said open end and outside wall of said container and saidcap are longitudinally slidable relative to each other and form aslidable seal; and (d) closing said protective container with said capto protect said swab and microbiological sample from the environmentexternal of said container.
 5. A method of collecting microbiologicalsamples comprising:(a) contacting a microbiological sampling site with apolyurethane foam swabbing tip which is non-growth inhibiting to viablemicroorganisms without transport media; and (b) removing amicrobiological sample from said sampling site with said swabbing tip.6. A method of collecting microbiological samples comprising:(a)contacting a microbiological sampling site with a polyurethane foamswabbing tip which is non-growth inhibiting to N. meningitidis and N.gonorrhoeae without transport media; and (b) removing a microbiologicalsample from said sampling site with said swabbing tip.
 7. The method ofclaim 6 wherein said microbiological sample site is the upperrespiratory area of a human patient.
 8. A method for immunologicallydetecting microbiological organisms comprising:(a) contacting a samplesite with a polyurethane foam swabbing tip which is non-growthinhibiting to viable microorganisms, connected to a shaft comprising afirst and second end wherein the second end of said shaft is connectedto a cap comprising an exterior and interior face; (b) removing amicrobiological sample from said sampling site with said swabbing tip;(c) inserting the swabbing tip with the microbiological sample into aprotective container without transport media, said container comprisinga longitudinally extending body comprising an open end, a closed end,and an inside and outside wall, wherein said open end and outside wallof said container and said cap are longitudinally slidable relative toeach other and form a slidable seal; (d) closing said protectivecontainer with said cap to protect said swab and microbiological samplefrom the environment external of said container; and (e) subjecting saidmicrobiological sample to an immunoassay for detecting and identifyingmicroorganisms.
 9. A method for immunologically detectingmicrobiological organisms comprising:(a) contacting a sample site with apolyurethane foam swabbing tip which is a non-growth inhibiting to N.meningitidis and N. gonorrhoeae, connected to a shaft comprising a firstand second end wherein the second end of said shaft is connected to acap comprising an exterior and interior face; (b) removing amicrobiological sample from said sampling site with said swabbing tip;and (c) inserting the swabbing tip with the microbiological sample intoa protective container without transport media, said containercomprising a longitudinally extending body comprising an open end, aclosed end, and an inside and outside wall, wherein said open end andoutside wall of said container and said cap are longitudinally slidablerelative to each other and form a slidable seal; (d) closing saidprotective container with said cap to protect said swab andmicrobiological sample from the environment external of said container;and (e) subjecting said microbiological sample to an immunoassay fordetecting and identifying microorganisms.
 10. A device for collectingmicrobiological samples comprising:a shaft comprising a first and secondend; and a polyurethane foam swabbing tip which is non-growth inhibitingto viable microorganisms without transport media, connected to saidsecond end of said shaft.
 11. A device for collecting microorganismscomprising:a shaft comprising a first and second end; and a polyurethanefoam swabbing tip which is non-growth inhibiting to N. meningitidis andN. gonorrhoeae without transport media connected to said second end ofsaid shaft.
 12. A method for immunologically detecting microbiologicalorganisms comprising:(a) contacting a sample site with a polyurethanefoam swabbing tip which is non-growth inhibiting to viablemicroorganisms, without transport media connected to a shaft comprisinga first and second end; (b) removing a microbiological sample from saidsampling site with said swabbing tip; and (c) subjecting saidmicrobiological sample to an immunoassay for detecting and identifyingmicroorganisms.
 13. A method for immunologically detectingmicrobiological organisms comprising:(a) contacting a sample site with apolyurethane foam swabbing tip which is non-growth inhibiting to N.meningitidis and N. gonorrhoeae, without transport media connected to ashaft comprising a first and second end; (b) removing a microbiologicalsample from said sampling site with said swabbing tip; and (c)subjecting said microbiological sample to an immunoassay for detectingand identifying microorganisms.